/******************************************************************************
 * @file     main.c
 * @version  V3.00
 * $Revision: 1 $
 * $Date: 17/08/07 2:05p $
 * @brief    Use timer to wake up system from Power-down mode periodically.
 * @note
 * Copyright (C) 2017 Nuvoton Technology Corp. All rights reserved.
*****************************************************************************/
#include <stdio.h>
#include "NM1120.h"


void TMR0_IRQHandler(void)
{
    /* Clear wake up flag */
    TIMER_ClearWakeupFlag(TIMER0);
    /* Clear interrupt flag */
    TIMER_ClearIntFlag(TIMER0);
}

void SYS_Init(void)
{
    /* Unlock protected registers */
    SYS_UnlockReg();

    /* Enable 48MHz HIRC */
    CLK->PWRCTL = CLK->PWRCTL | CLK_PWRCTL_HIRCEN_Msk;

    /* Waiting for 48MHz clock ready */
    CLK_WaitClockReady(CLK_STATUS_HIRCSTB_Msk);

    /* HCLK Clock source from HIRC */
    CLK->CLKSEL0 = CLK->CLKSEL0 | CLK_HCLK_SRC_HIRC;

    /* Enable IP clock */
    CLK->APBCLK = CLK->APBCLK | CLK_APBCLK_USCI0CKEN_Msk;
    CLK->APBCLK = CLK->APBCLK | CLK_APBCLK_TMR0CKEN_Msk;

    /* Select IP clock source */
    CLK->CLKSEL1 = CLK->CLKSEL1 & ~(CLK_CLKSEL1_TMR0SEL_Msk) | CLK_TMR0_SRC_LIRC;

    /* Update System Core Clock */
    /* User can use SystemCoreClockUpdate() to calculate SystemCoreClock and cyclesPerUs automatically. */
    SystemCoreClockUpdate();

    /* USCI-Uart0-GPD5(TX) + GPD6(RX) */
    /* Set GPD multi-function pins for USCI UART0 GPD5(TX) and GPD6(RX) */
    SYS->GPD_MFP = SYS->GPD_MFP & ~(SYS_GPD_MFP_PD5MFP_Msk | SYS_GPD_MFP_PD6MFP_Msk) | (SYS_GPD_MFP_PD5_UART0_TXD | SYS_GPD_MFP_PD6_UART0_RXD);

    /* Set GPD5 as output mode and GPD6 as Input mode */
    PD->MODE = (PD->MODE & ~(GPIO_MODE_MODE5_Msk | GPIO_MODE_MODE6_Msk)) | (GPIO_MODE_OUTPUT << GPIO_MODE_MODE5_Pos);

    /* Lock protected registers */
    SYS_LockReg();
}


int main()
{
    int i = 0;

    SYS_Init();

    /* Init USCI UART0 to 115200-8n1 for print message */
    UUART_Open(UUART0, 115200);

    /*Initial Timer0 to periodic mode with 1Hz */
    TIMER0->CMP = __LIRC;
    TIMER_SET_PRESCALE_VALUE(TIMER0, 0);
    TIMER0->CTL = TIMER0->CTL | TIMER_PERIODIC_MODE;

    /* Enable timer wake up system */
    TIMER0->CTL |= TIMER_CTL_WKEN_Msk;
    /* Enable Timer0 interrupt */
    TIMER0->CTL |= TIMER_CTL_INTEN_Msk;
    NVIC_EnableIRQ(TMR0_IRQn);
    /* Start Timer0 counting */
    TIMER0->CTL |= TIMER_CTL_CNTEN_Msk;
    /* Unlock protected registers */
    SYS_UnlockReg();
    while(1) {
        CLK_PowerDown();
        printf("Wake %d\n", i++);

        /* Wait USCI UART buffer empty to get a cleaner console out */
        UUART0->PROTSTS = (UUART_PROTSTS_TXENDIF_Msk | UUART_PROTSTS_TXSTIF_Msk);
        while(!((UUART0->BUFSTS & UUART_BUFSTS_TXEMPTY_Msk) >> UUART_BUFSTS_TXEMPTY_Pos));
        if(UUART0->PROTSTS & UUART_PROTSTS_TXSTIF_Msk)
            while((UUART0->PROTSTS & UUART_PROTSTS_TXENDIF_Msk) != UUART_PROTSTS_TXENDIF_Msk);
    }
}

/*** (C) COPYRIGHT 2017 Nuvoton Technology Corp. ***/
